Example operation of a mechanical switch involves rectilinear movement of a switch actuator that compresses an elastic domed keypad as it slides within a switch housing, relatively speaking, in the downward direction into compressive contact with the domed keypad. “Spring” force provided by the domed keypad provides tactile feel as the user pushes down on the switch button coupled to the switch actuator. That spring force also serves an upward biasing force that returns the actuator to its topmost or “rest” position, when the user releases the switch.
In plastic switch assemblies configured according to the above details, plastic-to-plastic contact occurs between the actuator and its housing, at least in designs where the switch housing retains the actuator and defines the limit of its upward travel on the return stroke. Certain applications, such as seat-control buttons in an automotive context, disfavor the “clicking” noise produced on the return stroke of such switches. However, manufacturing constraints and the need to retain tactile feel complicate noise-reduction modifications.